BoilerFaultCodesYour boiler has shut down because the hot water has reached a temperature that is dangerously high.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temperature too high during domestic hot water (DHW) demand
What causes this fault?
This fault occurs when the water meant for your taps becomes dangerously overheated, triggering a safety shutdown to prevent scalding. The most common reason is that the boiler's internal sensors are giving incorrect readings, or the flow of water through the heat exchanger is being restricted by limescale or a mechanical failure. In some cases, a faulty valve may be sending heat to the wrong place, causing the temperature to spike rapidly.
This fault is often more noticeable in summer when the incoming mains water is naturally warmer, making it easier for the boiler to exceed its maximum safety temperature.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like F002 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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